Darwin used multiple lines of evidence to support his theory of evolution by natural selection -- fossil evidence, biogeographical evidence, and anatomical evidence.

I look at the geological record as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a few lines. Each word of the slowly-changing language, more or less different in the successive chapters, may represent the forms of life, which are entombed in our consecutive formations, and which falsely appear to have been abruptly introduced.

(From Charles Darwin, On The Origin of Species. [New York: The Modern Library, 1993] p. 443)

Fossils are rare, and it is difficult to find ancestral fossil species that show a line of evolution from a common ancestor. Yet, scientists have amassed fossil data that explains much of the evolutionary history of life. Use the resources listed below to gather information on fossil evidence.